secretary of state hillary clinton warned that was a red line. a short while ago, president obama issued this warning from washington. today, i want to make it absolutely clear to assad andd those -- and those under his command, the world is watching. the use of chemical weapons is an would be totally -- is and would be totally acceptable. if you make them tragic mistake of using these weapons, there will be consequences and you will be held accountable. >> i discussed his strong words to syria's leaders with the bbc 's state department correspondent. while u.s. officials talking about serious chemical weapons -- wh yare -- why are u.s. officials talking about syria's chemical weapons now? >> officials have been quoted as saying they have seen activity, that these weapons are being moved around, possibly in preparation for their use. it is very difficult to read the assad government and find out exactly what they are doing. are they trying to protect them? are they trying to bluff? we have heard from certain officials saying they have no intentio